Buggy code:
public class TableVisualizer extends AbstractVisualizer implements Clearable { private static final Logger log = LoggingManager . getLoggerForClass ( ) ; private final String [ ] COLUMNS = new String [ ] { JMeterUtils . getResString ( "table_visualizer_sample_num" ) , JMeterUtils . getResString ( "table_visualizer_start_time" ) , JMeterUtils . getResString ( "table_visualizer_thread_name" ) , JMeterUtils . getResString ( "sampler_label" ) , JMeterUtils . getResString ( "table_visualizer_sample_time" ) , JMeterUtils . getResString ( "success?" ) , JMeterUtils . getResString ( "table_visualizer_bytes" ) } ; private ObjectTableModel model = null ; private JTable table = null ; private JTextField dataField = null ; private JTextField averageField = null ; private JTextField deviationField = null ; private JTextField noSamplesField = null ; private JScrollPane tableScrollPanel = null ; private transient Calculator calc = new Calculator ( ) ; private long currentData = 0 ; private Format format = new SimpleDateFormat ( "HH:mm:ss.SSS" ) ; public TableVisualizer ( ) { } public static boolean testFunctors ( ) { } public String getLabelResource ( ) { } protected synchronized void updateTextFields ( ) { } public void add ( SampleResult res ) { } public synchronized void clear ( ) { } public String toString ( ) { } private void init ( ) { this . setLayout ( new BorderLayout ( ) ) ; JPanel mainPanel = new JPanel ( ) ; Border margin = new EmptyBorder ( 10 , 10 , 5 , 10 ) ; mainPanel . setBorder ( margin ) ; <START_BUG> mainPanel . setLayout ( new VerticalLayout ( 5 , VerticalLayout . LEFT ) ) ; <END_BUG> mainPanel . add ( makeTitlePanel ( ) ) ; table = new JTable ( model ) ; tableScrollPanel = new JScrollPane ( table ) ; tableScrollPanel . setViewportBorder ( BorderFactory . createEmptyBorder ( 2 , 2 , 2 , 2 ) ) ; JPanel dataPanel = new JPanel ( ) ; JLabel dataLabel = new JLabel ( JMeterUtils . getResString ( "graph_results_latest_sample" ) ) ; dataLabel . setForeground ( Color . black ) ; dataField = new JTextField ( 5 ) ; dataField . setBorder ( BorderFactory . createEmptyBorder ( 0 , 0 , 0 , 0 ) ) ; dataField . setEditable ( false ) ; dataField . setForeground ( Color . black ) ; dataField . setBackground ( getBackground ( ) ) ; dataPanel . add ( dataLabel ) ; dataPanel . add ( dataField ) ; JPanel averagePanel = new JPanel ( ) ; JLabel averageLabel = new JLabel ( JMeterUtils . getResString ( "graph_results_average" ) ) ; averageLabel . setForeground ( Color . blue ) ; averageField = new JTextField ( 5 ) ; averageField . setBorder ( BorderFactory . createEmptyBorder ( 0 , 0 , 0 , 0 ) ) ; averageField . setEditable ( false ) ; averageField . setForeground ( Color . blue ) ; averageField . setBackground ( getBackground ( ) ) ; averagePanel . add ( averageLabel ) ; averagePanel . add ( averageField ) ; JPanel deviationPanel = new JPanel ( ) ; JLabel deviationLabel = new JLabel ( JMeterUtils . getResString ( "graph_results_deviation" ) ) ; deviationLabel . setForeground ( Color . red ) ; deviationField = new JTextField ( 5 ) ; deviationField . setBorder ( BorderFactory . createEmptyBorder ( 0 , 0 , 0 , 0 ) ) ; deviationField . setEditable ( false ) ; deviationField . setForeground ( Color . red ) ; deviationField . setBackground ( getBackground ( ) ) ; deviationPanel . add ( deviationLabel ) ; deviationPanel . add ( deviationField ) ; JPanel noSamplesPanel = new JPanel ( ) ; JLabel noSamplesLabel = new JLabel ( JMeterUtils . getResString ( "graph_results_no_samples" ) ) ; noSamplesField = new JTextField ( 10 ) ; noSamplesField . setBorder ( BorderFactory . createEmptyBorder ( 0 , 0 , 0 , 0 ) ) ; noSamplesField . setEditable ( false ) ; noSamplesField . setForeground ( Color . black ) ; noSamplesField . setBackground ( getBackground ( ) ) ; noSamplesPanel . add ( noSamplesLabel ) ; noSamplesPanel . add ( noSamplesField ) ; JPanel tableInfoPanel = new JPanel ( ) ; tableInfoPanel . setLayout ( new FlowLayout ( ) ) ; tableInfoPanel . setBorder ( BorderFactory . createEmptyBorder ( 0 , 0 , 0 , 0 ) ) ; tableInfoPanel . add ( noSamplesPanel ) ; tableInfoPanel . add ( dataPanel ) ; tableInfoPanel . add ( averagePanel ) ; tableInfoPanel . add ( deviationPanel ) ; JPanel tablePanel = new JPanel ( ) ; tablePanel . setLayout ( new BorderLayout ( ) ) ; tablePanel . add ( tableScrollPanel , BorderLayout . CENTER ) ; tablePanel . add ( tableInfoPanel , BorderLayout . SOUTH ) ; this . add ( mainPanel , BorderLayout . NORTH ) ; this . add ( tablePanel , BorderLayout . CENTER ) ; } }

Fix:
mainPanel . setLayout ( new VerticalLayout ( 5 , VerticalLayout . BOTH ) ) ;